This invention is in the field of activatable infrared emitters. Such emitters have various uses, such as decoys and markers and are becoming more important with the increases in number and use of infrared detectors and imagers. For point sources, incandescent light bulbs are excellent, but for larger or more diffuse sources, other schemes must be used. U.S. Pat. No. 3,878,396, for example, shows an infrared source which is activated when water is added to a mixture of P.sub.2 O.sub.5, BaO, and manganese nitride. U.S. Pat. No. 3,596,098 shows an infrared source in the shape of a disc, with a pyrotecnic material contained within and confined to the disc as the material acts. These schemes seem to work fine for their intended purposes, but none fills the need for an extremely cheap, readily activatable, diffuse infrared source with indefinite storage life and a relatively long service life. The instant invention fills this need, and can be readily made in the field with locally-procured materials.